December 28, 2011 10:53pm ESTDecember 26, 2011 8:00am ESTAlbert Pujols' decision to join the Angels is among the top stories in baseball heading into 2012. But is there a story that will be even more fascinating to watch in the new year?

As the calendar flips to 2012, there are plenty of intriguing issues and trends to track across all of sports. Sporting News looks at three story lines to watch in each sport, beginning with baseball:

1. Bobby Valentine in the Red Sox dugout

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Boston won 90 games in 2011 but only seven in September, and that collapse cost the team a playoff berth and manager Terry Francona his spot on the bench. Soon after, general manager Theo Epstein left to run the Cubs, resulting in Red Sox ownership playing a major role in selecting the new skipper.

Valentine hasn’t managed in the majors since 2002, but he will have plenty of talent at his disposal. The lineup features Adrian Gonzalez, Jacoby Ellsbury, David Ortiz, Dustin Pedroia, Kevin Youkilis and Carl Crawford, while the rotation includes Josh Beckett, Jon Lester and Clay Buchholz.

2. The new-look Angels and Marlins

They dominated the winter meetings and vaulted to contender status, thanks to their checkbooks.

Los Angeles added first baseman Albert Pujols to its lineup and lefthander C.J. Wilson to its already strong rotation, establishing itself as the favorite in the American League West and lead horse in the Southern California baseball scene. The Dodgers franchise has lost some of its shine because of its ongoing sale saga and financial issues. If the Dodgers disappoint again and the Angels meet expectations, it could create a seismic shift among the area’s baseball loyalists.

In South Beach, the Marlins have more than a new name (Florida is out, Miami is in), ballpark and uniform/logo. They also hired manager Ozzie Guillen and added a trio of big-time free agents: shortstop Jose Reyes, lefthander Mark Buehrle and closer Heath Bell. The newcomers—added to an already talented roster—make the Marlins a threat in the National League East.

3. Bryce Harper’s debut

Harper, the Nationals’ top overall pick in the 2010 draft, will reach the majors this season—but perhaps not as quickly as once believed. Blame baseball’s new collective bargaining agreement, which increases the percentage of players classified as “Super Twos” in the arbitration process.

Under the old agreement, general managers often would wait until late May to promote a prospect in order to avoid giving him Super Two status. In the new agreement, that date could be pushed back as far as late June. That means Harper, 19, might have to play an extra month in the minors, even if he is mashing at Class AAA.